title: Bilateral trochlear nerve palsy with arachnoid cyst of the quadrigeminal cistern.
abstract: OBJECTIVE
  To report bilateral trochlear nerve palsy and its magnetic resonance imaging characteristics in a patient with an arachnoid cyst of the quadrigeminal cistern.
  
  
  METHODS
  We performed magnetic resonance imaging of the brainstem of a 54-year-old man who had bilateral trochlear nerve palsy and mild truncal ataxia.
  
  
  RESULTS
  Magnetic resonance imaging disclosed an arachnoid cyst of the quadrigeminal cistern with enlargement of the lateral, third, and fourth ventricles. The tectum of the midbrain and the ambient and interpeduncular cisterns were markedly compressed by the arachnoid cyst.
  
  
  CONCLUSIONS
  These findings suggest that the bilateral trochlear nerve palsy in this patient was caused by the arachnoid cyst of the quadrigeminal cistern.
authors.affiliation: Department of Ophthalmology, Sapporo Medical University, School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ohtsuka
authors.forename: M
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamura
mesh_terms: D016080:Arachnoid Cysts / Q000150:complications* / Q000175:diagnosis; D001259:Ataxia / Q000209:etiology; D003389:Cranial Nerve Diseases / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010243:Paralysis / Q000175:diagnosis / Q000209:etiology*; D003336:Tectum Mesencephali / Q000473:pathology*; D014321:Trochlear Nerve / Q000473:pathology*; D014792:Visual Acuity